This proposal relates to the invention of a system for automatic multiple- parallel synthesis (or sequencing) of biologically important polymers. Chemically synthesized peptides, each of which start at a more advanced position along previously sequenced coding DNA (i.e., walk along the gene) are now being used to locate antigen sites or epitopes to which antibodies (which have been produced by exposure to complete proteins), or autoantibodies react. The aim is to produce artificial peptide-based vaccines against HIV and other pathogenic viruses, and to identify epitopes involved in autoimmunity. In our system, a series of sequential reactions are carried out in parallel, with a preprogrammed amino acid for each parrellel addition reaction kept separate, with methods for keeping the synthesis (or cleavage sites) separate, the reagent streams accurately apportioned and separate, and individual reagents effectively segmented, with positive methods for moving small volumes through the systems, with reagent volumes kept to a minimum, and with methods for positively washing attachment sites free of reagents. The principles on which the system is based are also applicable to the synthesis of oligonucleotides and eventually to amino acid sequencing. The proposed system can be built on either a micro or preparative scale.